This invention relates to an improved adjustable ring nut for supporting pipe hangers.
Pipe hanger assemblies typically include a pipe hanger strap or other such member which surrounds and supports the pipe or other object to be suspended from an overhead support. A pipe hanger rod is connected on its upper end to a ceiling beam or other overhead supporting structure, and the lower end of the rod is connected to the pipe hanger strap. One common way of connecting the lower end of the rod is to use a steel ring nut which has a tubular exterior with an outwardly extending flange at its lower end and has a threaded interior. The upper end of the ring nut extends through holes in the pipe hanger strap but the flange on the lower end is larger than the hole in the strap. Thus, when the nut is threaded onto the lower end of the pipe hanger rod, the flange supports the pipe hanger. It is difficult to have access to the flange for rotating the ring nut in adjusting its position on the support rod. Thus the exterior of the upper tubular portion is usually knurled or otherwise formed to facilitate gripping so that the ring nut can be turned from above the pipe hanger strap.
Ring nuts of the type described above are quite satisfactory from a performance standpoint. However, one drawback is that they are relatively expensive since it is a specially machined component having interior threads. While the individual cost of one ring nut is not great, the huge volumes of the component are utilized, with the result that any cost reductions are important.
A much less expensive approach that is also utilized is to simply insert the pipe hanger rod through the opening in the pipe hanger strap and thread a regular nut onto the lower end of the rod. The exterior dimension of the nut is greater than the hole in the strap so that the load is transmitted directly to the nut. The major shortcoming of this approach is that it is difficult to have access to the nut to rotate it in making the necessary adjustments in the height of the pipe hanger strap.
Accordingly, the need exists for a method of adjustably connecting the pipe hanger strap and the pipe hanger rod in a manner that is as convenient as the currently-used ring nuts but is less expensive.